pkg/metricsx: Initial commit

2 files changed, 83 insertions, 0 deletions

diff --git a/pkg/metricsx/metricsx.go b/pkg/metricsx/metricsx.go
new file mode 100644
index 0000000..bc37843
--- /dev/null
+++ b/pkg/metricsx/metricsx.go
@@ -0,0 +1,39 @@
+// Package metricsx extends github.com/VictoriaMetrics/metrics.
+package metricsx
+
+import "strings"
+
+func splitName(name string) (base, arg string) {
+	if n := len(name); n != 0 {
+		base = name
+		for i, r := range base {
+			if r == '{' {
+				if j := len(base) - 1; j > i && base[j] == '}' {
+					base, arg = base[:i], base[i+1:j]
+					break
+				}
+			}
+		}
+	}
+	return
+}
+
+func formatName(base, arg string, args ...string) string {
+	var b strings.Builder
+	b.WriteString(base)
+	b.WriteByte('{')
+	if arg != "" {
+		b.WriteString(arg)
+	}
+	for i := 1; i < len(args); i += 2 {
+		if arg != "" || i > 1 {
+			b.WriteByte(',')
+		}
+		b.WriteString(args[i-1])
+		b.WriteString("=\"")
+		b.WriteString(args[i])
+		b.WriteByte('"')
+	}
+	b.WriteByte('}')
+	return b.String()
+}
diff --git a/pkg/metricsx/metricsx_test.go b/pkg/metricsx/metricsx_test.go
new file mode 100644
index 0000000..5bcf8ab
--- /dev/null
+++ b/pkg/metricsx/metricsx_test.go
@@ -0,0 +1,44 @@
+package metricsx
+
+import "testing"
+
+func TestSplitName(t *testing.T) {
+	for _, c := range [][3]string{
+		// valid
+		{`test`, `test`, ``},
+		{`test{}`, `test`, ``},
+		{`test{test=""}`, `test`, `test=""`},
+		{`test{test="{}"}`, `test`, `test="{}"`},
+
+		// invalid
+		{``, ``, ``},
+		{`test{`, `test{`, ``},
+		{`test}`, `test}`, ``},
+		{`test}{`, `test}{`, ``},
+		{`test{}{}`, `test`, `}{`},
+		{`test{}{test}`, `test`, `}{test`},
+		{`test{test{}}`, `test`, `test{}`},
+		{`test{}{test{}}`, `test`, `}{test{}`},
+	} {
+		name, xbase, xarg := c[0], c[1], c[2]
+		if base, arg := splitName(name); base != xbase || arg != xarg {
+			t.Errorf("split %#q: expected (%#q, %#q), got (%#q, %#q)", name, xbase, xarg, base, arg)
+		}
+	}
+}
+
+func TestFormatName(t *testing.T) {
+	for _, c := range [][]string{
+		{`test{}`, `test`, ``},
+		{`test{a="1"}`, `test`, `a="1"`},
+		{`test{a="1",b="2"}`, `test`, `a="1"`, `b`, `2`},
+		{`test{a="1",b="2"}`, `test`, `a="1",b="2"`},
+		{`test{a="1",b="2",c="3"}`, `test`, `a="1"`, `b`, `2`, `c`, `3`},
+		{`test{a="1",b="2",c="3"}`, `test`, `a="1",b="2"`, `c`, `3`},
+	} {
+		exp, base, arg, args := c[0], c[1], c[2], c[3:]
+		if act := formatName(base, arg, args...); act != exp {
+			t.Errorf("format (%#q, %#q, %#q, %#q): expected %#q, got %#q", exp, base, arg, args, exp, act)
+		}
+	}
+}